Air brake for motor vehicles



April 1, 1924;

D.G.DUTY

AIR BRAKE FOR MOTOR VEHICLES Filed April 17. 1923 2 Sheets-Sheet 1 April1,1924; I 1,488,742

4 f D. G. DUTY AIR BRAKE FOR MOTOR VEHICLES Filed April 17 1925 2 Sheets-Sheet 2 Patented Apr. il, 1924.

' nonsnr G. DUTY, or rENNsBoao, www VIRGINIA.

AIR BRAKE FOR MOTOR VEHICLES. f

Application led April 17, 1928. Serial No. 632,667.

To all whom t may concern: Y

Be it known that DoRsEY Gr. DUTY, a citizen of the United States of America, residing at Pennsboro, in the county of Ritchie and State of West Virginia, has invented certain new and useful Improvements in Air Brakes for Motor Vehicles, of which the following is a specification.

My invention relates to brakes for motor vehicles, and more particularly to air brakes for such vehicles.

One of the objects vof the invention is to provide simple and easily actuated means for quickly releasing the clutch and applying the brakes without the use of the feet.

Another object of the invention is to provide means whereby the operator can with minimum effort gradually apply the brakes without interfering with the usual foot pedal mechanism.

Other objects-and advantages will be in part described and lin part obvious as the specification` is proceeded with.

'In the accompanying drawings forming part of the specification:

Figurelisa -pldan view of an automobile with my invention thereon;

Figure 2. is a'horizontal section through the air control member l 1 `Figure '3 is a partial side elevation of'Figure'1;and'-v A, A

vFigure 4;,-is horizontal section of a modified form of air' control member.

Referring more particularly to the drawings, 1, denotes the frame of an automobile supported upon front and rear wheels 2 and.

3 respectively. The clutch ,(not shown) is actuated in the usual ,way by means of` foot pedal 4, ixedly mounted on the clutch shaft 5, while the brakes '6, on the rear wheels 3, are connected up with the foot pedal 7, loosely mounted onthe shaft 5. The invention also contemplates the use of com-w pressed air for. actuating the brake mechanism and for throwing out the clutch inde` v pendently of the foot pedals.

` A compressed airltankvSf, suitably mounted' on the frame 1, is connected to the explosion f chamber (not shown) of the engine 9.by

'means of a transverse pipe 10,'leading from the tank and connected to one end of a longitudinally disposed pipe. 11, by means of a T 12,- the. pipe 11, being connected 4at 'its other end to an elbow 13, 1nv turny communicating withtlie explosion chamber. vThe elbow; 13,

is provided with a suitable check valve 14. When the engine is runningcompressed air will be constantly iorced into the tank 8, in an obvious manner. Of course it is only necessary that the tank 8 be in communication with the explosion chamber of but one cylinder of the engine.

A short longitudinally disposed` pipe 15, connects the pipe l0, with the inlet o ening 16 of an air pressure control member l ,provided with an outlet 18, through which the compressed air passes into the pipe 19, and thence into one end of the brake control cylinder 20. The piston rod 21, of the piston 221, of the cylinder 20, is pivotally connected to a rock arm 23, which in turn is ivotally connected to the frame 1, by a link) 24, the rod 23, being provided with a series of openings 25, whereby the point of connection with the link 24, may be adjusted to obtain the desired leverage. A rod 26 is connected at its forward end to the rod 23, intermediate the ends o the latter `and at its rear end is connected to the crank arm 27, of the usual brake rods 28 and 29 of the brake 6.

It will t-hus be seen that forward movement of the rod 26, rocks the crank arm 27, and the rods 28, in a clockwise direction,

thus pulling the rods 29, forwardly and tween the superposed edges of which is clamped a diaphragm 33 separating the air -chamber 34v into upper and lower air tight compartments, by means of bolts 34.- The lcastings 31 and 32 which form therebetween the air chamber 34:', are provided with the oppositely disposed cylindrical ortions or projections 35 and 36 respective y and the casting 31,' is formed with an exhaust opening 37, connected with an exhaust pipe 38, the opening 37, being opposite the outlet opening 18, in the casting 32, previously described as leading to the brake control.. cylinder 20.

jection 35, is connected to a plunger 46, at

its lower end, and its upper end is resiliently held against the lever 40, by the action of coil spring 47. This spring 47, encircles the upper end of a anged tubular valve'seat member 48, projecting up through central aligned openings in the diaphragm 33, and a plate 49, respectively, the said plate belng superposed on the dia hragm. The tubular member 48, and the p ate 49, are threadedly connected together as at 50, the diaphragm 33, being clamped between the plate' 49, and the flanges 51, of the tubular member 48,

when the parts are screwedl up as illustrated in Figure 2.

A cylindrical valve 52, having its upper portion provided with longitudinal grooves 54, projecting into the tubular valve seat member 48, is adapted to be resiliently held in Figure 2 position and normally below the valve seat 55, by means of a coil spring 56. The spring 56, bears at opposite ends against the valve 52 and against a valve seat 53, in the projection 36, of the casting 32.

- A second or lower valve 57, similar to the valve 52, is formed with a threaded recess in its upper end into which is threaded as' at 58, the threaded projection 59, on the upper valve 52. Consequently they coil spring 56, also serves to normally hold the valve 57, closed against its seat 53.

The operation of the brakes b compressed air is accomplished in the fo lowing manner:

The operator presses down on the lever 4() thereby compressing the spring 47, and in turn forcing the diaphragm downwardly until the' valve seat 55, engages the valve 52.

whereupon compressed air direct A'from the explosion chamber of the engine enters inlet opening 16, and passes upwardly through the grooves 60, into the lower" part of the chamber 34', and thence out through pipe 19 to cylinder 20, thus causing the brakes to be applied.

It may here be noted that theiair pressure can be gradually applied with little eii'ort on the part of the operator, it merely being necessary for the latter to slowly push the lever 40, to the limit of its movement to obtain the maximum air pressure. The brakes4 will thus be gradually and smoothly applied, with little increased eiort on the part of the operator as the tension on spring 56, increases toward the end of the move ment of the knee lever. This movement of the lever also seats the valve 52, and prevents air escaping through the blow ofi' outlet 37, leadin from the air pressure control member The clutch not shown) can be operated either by the oot pedal 4, or by means of compressed air as follows: A clutch lever 68, clutch cylinder 69, and pressure control member are provided, identical with the 75 brake lever 40, brake cylinder 20, and brake pressure control member 17, respectively, the Vonly difference being that. the position of the member 70, is just the reverse of that of the member 17 When the operator 80 pushes the lever 68 downwardly the air con- .trol mechanism is operated in the identical manner described in connection with the operation of the brakes. The pipe 10, leading from the air tank 8, connects up with the inlet opening 16, of the member 7 in the same manner as the branch pipe 15, connects with the air pressure control member 17. A pipe 71, connects the outlet opening 18, of the member 70, with the clutch operaty ing cylinder 69. Consequently when the lever 68, is actuatedvthe piston of cylinder 69, will be moved forwardly and the clutch shaft 5, will be rocked through the medium v of the rod 73, which connects the shaft 5,/ with the piston of the cylinder 62, thereby throwing out the clutch not shown).

The air pressure control members 17 and 70 are identical and therefore it is deemed unnecessary to describe the structure and operation of both in detail It will be' noted that the air pressure control members receive the air from a common source and that the one can be used without the other, or both can be used at the same time, also 105 that one -or both of the foot pedals'can be usedindependently of either of the air controlsfor simultaneously therewith. 4 In order to remove' the pressure from the brakes the lever 40, is released, whereupon 1.10

" the compressed air entering inlet opening 16, Continued downward movement of the lever v40 forces the valve 57 from its seat 53,

elevates the diaphragm to its normal horizontal positions thus unseating the valve 52. The valve 57 immediately closes and the upperand lower portions of the .cham- 11,5

ber 34, being in .communication with each other through the grooves 54, invalve 52 the pressure becomes equal on both sides ofi.-` Y I.

the diaphragm as the compressed air in the chamber 34, escapes through the exhaustX pressure control member comprising' a cylinder 80. having a cover "81j provided,w1th an upstanding tubular rejection 82. A hand lever 83 ,is pivotal y mounted at one end as at 84, 'in a recess 85, a pawl 86 on thel ,130

lever being adapted to engagea rack 87, on

' in a vertical opening 89, in the projection 82, is connected to a plunger 90, at its lower end, and at its upper ends is resiliently held vagainst the lever 83, by the action of coil spring 91. ,This spring 91, rests against the upper end of a flanged tubular member 92, which in turn rests upon the top of a piston 93, there being a reinforcing plate 94, von the under side of the piston, the .piston being clamped between this plate and the flanges 95 by any suitable fastening means (not shown).

A cylindrical valve 96, having its upper portion provided with longitudinal grooves 97, projects up through the plate 94, and piston 93 and extends into the flanged tubular member 92. A secondor lowervalve 98, similar to the valve 96, is formed with a threaded recess in its upper end into which is threaded as at .99, the threaded projection 100, on the upper valve 96. This Dlower valve 98, which is formed with longitudinal grooves 101 is resiliently held against the valve seat 102,.in the inlet opening 103, connected to the explosion chamber ofthe engine, by means of a coil spring 104, bearing at its upper end against the flange 105, of valve 96, and at its lower end against the lower end of the cylinder 80.

The-opening 106, in the cylinder beneath the piston 93, leads via pipe 19, to the piston 20, and the exhaust opening, 107 connects with exhaust ferred form of my invention.

As the operaftion of the-modification is pipe 38 as in the pref Having thus described my invention what I claim as my invention is :V

In combination a motor. vehicle having wheels and brakes therefor, a brake cylinder and piston for actuatin the brakes by compressed air, an air supp y in communication with the explosion chamber of the engine and with said brake cylinder, and pressure control means for gradually feeding the compressed air to the brake actuating means, said pressure control means comprising an air chamber, a displaceable member in said chamber dividing the same intov upper and lower air tight compartments, an

inlet opening for connecting said lower compartment with the explosive chamber of the engine, a spring ressed lower valve normally closing sai opening, said displacement member having an opening normally communicating with said upper and lower compartments, an uppervalve connected to said first mentioned valve for closing said opening in said displaceable member, means for forcing said displaceable member downwardly against said second valve to close the opening in said displaceable member, said upper compartment having an exhaust outlet -of smaller size than said air inlet opening, and said lower compartment having an outlet identical in size to said exhaust outlet leading to said brake cylinder, and means for forcing said displaceable member against said second valve to cause said upper valve to close and said lower valve to open. p

In testimony whereof I alix my signature in' presence of two witnesses.

DORSEY G. DUTY. Witnesses:

H. V. ADAMS,

I. L. FoRDYoE. 

